EP 0105661 B1 19861210 - APPARATUS FOR INSPECTING A CIRCUIT PATTERN DRAWN ON A PHOTOMASK USED IN MANUFACTURING LARGE SCALE INTEGRATED CIRCUITS
Title (en)
APPARATUS FOR INSPECTING A CIRCUIT PATTERN DRAWN ON A PHOTOMASK USED IN MANUFACTURING LARGE SCALE INTEGRATED CIRCUITS
Publication
Application
Priority
JP 17398082 A 19821005
Abstract (en)
[origin: US4559603A] A photomask on which a circuit pattern is drawn is placed on an x-y table and is illuminated by a light source. A linear image sensor, on which the circuit pattern is imaged, measures the circuit pattern along the direction substantially perpendicular to a moving direction of the x-y table to generate an analog signal in units of measured positions on the mask. In order to eliminate the need for matching the size of the pixel to be measured with the pixel size of the design pattern data and allow effective detection of a defect smaller than the pixel size, an analog-to-digital converter is arranged to convert the analog signal to multi-level digital data, and a measured point calculation circuit calculates the position of the measured point in units smaller than the pixel size unit in accordance with the position of the x-y table. A reference data calculation circuit is provided to calculate multi-level reference digital data which is to be obtained when the design pattern is measured at a calculated measured point taking sensitivity distribution characteristics (including resolution characteristics of lens) of image sensor elements into consideration. A defect detector compares the measured data with the reference data to detect the presence or absence of defects of the circuit pattern on the photomask.
IPC 1-7
IPC 8 full level
H01L 21/66 (2006.01); G01N 21/88 (2006.01); G01N 21/956 (2006.01); G03F 1/00 (2006.01); G03F 1/84 (2012.01); H01L 21/027 (2006.01); H01L 21/30 (2006.01)
CPC (source: EP US)
G03F 1/84 (2013.01 - EP US); H01L 21/30 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
US 4559603 A 19851217; DD 212619 A5 19840815; DE 3368349 D1 19870122; EP 0105661 A1 19840418; EP 0105661 B1 19861210; JP S5963725 A 19840411; JP S633450 B2 19880123
DOCDB simple family (application)
US 53533483 A 19830923; DD 25530683 A 19830930; DE 3368349 T 19830920; EP 83305534 A 19830920; JP 17398082 A 19821005